1. Field of the Invention
The present invention relates to a composite for delivering active ingredients ingested orally to the large intestine without elution of the ingredients from the composite before reaching the large intestine, and a process for delivering the active ingredients with use of the composite.
2. Background Art
Colon cancer is one of the most prevalent cancers in the western countries. Patients of colon cancer has recently been increased also in Japan with the change of eating habits into western style. It is believed that the crisis of colon cancer can be eliminated by dietary care. However, such care actually can be practiced only with difficulty, since it requires expert knowledge and practice over a long period. Moreover, the prophylaxis of colon cancer with medicines or foods requires the lasting administration of them, so that these medicines or foods are also required to have the safety corresponding to or higher than that of ordinary medicines.
In the meantime, the mechanism of occurrence of colon cancer has been gradually elucidated in these years. It is believed as one of the possible mechanism of oncogenesis that lipid peroxide generated by the catalytic action of iron cation in the large intestine results in the damage of genes, which promotes the canceration of cells. It is thus believed essential for the prophylaxis of cells. It is thus believed essential for the prophylaxis of colon cancer to transform the iron cation into an innocuous form.
One of the present inventors has studied numerous materials which have been ingested by human for a long period and has found that phytins occurring in a wide variety of foods and having epidemiologically and cytologically established availability effectively work for transform the iron cation into an innocuous form in the large intestine (Cereal Chemistry, 59(6),525,1982). Intense lipid peroxide suppressive activity of phytins based on the iron cation scavenging ability is the most important activity for the prophylaxis of colon cancer (Molecular Medicine, 33(4), 404 (1996)).
However, phytins are also known to have a mineral ingestion inhibitory effect, and it is indicated that phytins are harmful when ingested in a large amount. Thus, there is a need of a composite which can pass as an innocuous form through the upper part of the small intestine which is major site of absorbing minerals such as iron or calcium and then release phytins at the large intestine that phytins act on and are absorbed in.
There are also the ingredients in addition to phytins which are preferably delivered only to the large intestine, such as Lactobacillus bifidus, anti-oxidants, and peptides.
There have been described various forms of composites which make possible active ingredients to be delivered to the large intestine including for example those in the form of capsule (Japanese Patent Laid-Open Publication Nos. 41422/1992, 225922/1992, 179618/1994, and 327634/1995), those coated with monolayer (Japanese Patent Laid-Open Publication Nos. 368321/1992, and 2701/1995), and those coated with chitosan and a special polymer (Japanese Patent Laid-Open Publication Nos. 34927/1991, 69333/1992, and 217924/1992). However, all of these composites have problems to be solved.
There is still a need of composites which are safe even in their successive administrations for a long period and can deliver the orally administered an active ingredient to the large intestine without elution of the ingredients from the composite before reaching the aimed site.